The invention concerns an LED lighting device for an AC voltage supply, with several LEDs forming a whole chain, whereby the LEDs are divided into LED part groups, whereby a supply voltage with alternating amplitude is present in the LED lighting device, whereby several LED part groups are positioned in series to each other and form an LED strand. The invention further concerns a method for operating the LED lighting device.
LED lights are increasingly used for lighting rooms and suchlike, as they can realise a high optical yield with a simultaneously low energy requirement. If one compares LED lights with classic filament lamps it is clear that the operation of lights with a classic filament bulb with an alternating voltage supply is much simpler than that of LED lights. Whilst classic filament lamps can be supplied with alternating voltage without problem, whereby one needs only monitor the height of the alternating voltage, LED lights can be operated only within a very limited voltage range. With an LED light a minimum voltage must be exceeded on the one hand in order to make the LED light up, whilst too much current flows through the LED light if too high a voltage is applied on the other, so that the same will fail after a short period of time without active cooling.
The working window with regard to working voltage for supplying the LED light is therefore comparatively small. In particular it is not possible to connect an LED light directly to an alternating voltage supply, as an operation of the LED light is not possible due to the widely varying voltage values.
DE 20 2011 105 404 U1 lists various voltage supply possibilities for LEDs, whereby it is also pointed out that light-emitting diodes can be supplied from an alternating voltage source, whereby a bridge rectifier is located between the light-emitting diodes together with possible series resistors, so that the light-emitting diodes are supplied with a pulsating current.